Protective device for electric circuits.



J. B. TAYLOR & D. S. CARPENTER.

PROTECTIVE DEVICE FOR ELEGTRIG CIRCUITS.

APPLIOATION FILED MAR.15, 1907.

925,054. Patented June 15, 1909.

' IWIIIH F WIT N E55 E5 J BINTVENTEI R5. v UHN .'AYLDR.

-' DAN"|E| 5.BARPENTEH DLJ ATT UNITED STATES PATENT OFFICE.

JOHN B. TAYLOR AND DANIEL S. CARPENTER, OF SOLIENEOTADY, NEW YORK,ASSIGNORS TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

PROTECTIVE DEVICE FOR ELECTRIC CIRCUITS.

N 0. 925,054. Specification of Letters Patent, PatentedJune 15, 1909.

Application filed March 15, 1907. swarm. 362,483.

- for electric" circuitsyand more particularly to rent To allwhom'itvmay concern:

Be it-known that we, J onN BQTA-YLOR and DANIEL S. CARPENTER,citiz'ensof the United States,]residing at. Schenectady, county ofSchenectady, State-of New York, have intion.

inye it'ion' -relates to: protective devices such devices usedconnectlon with tele-v same-poles-as high-tensiontransmission lines vaudits ."userfin' case of any abnormalcondithe originof such conditions;I

, In'th preferred The gap between the line discharge terminals "and thegrounded terminal may be adjusted so that it will break down only incase "of'a' dangerous rise in otential on the telephone I line caused bylig tning .or by a lead-of the transmission line comingintocontactIwith- I the telephone line,- while if an arc hojldsbetween aline terminal and the grounded'ter minala fuse blows, and if for anyrea'son'thisf does notfopen the circuit the arcmaybe, broken by movingthe support carrying the linejterminals. .;v

Our invention will best be understood. in

' connectionwith the accompanying drawings showingone embodiment ofour-invention merely for illustration, in which' v Figure 1' is a'erspective view of our protective device; i 2 a sectional view, showing.theline-disc arge terminals and zir 'pos'edto theindu'ctive effect o fthe curoivingthe'tra'nsmission line,'fa's ,Well as-"toexcessivepotential caused bylightning' or -by.'con,ta .1t et-w e thetransmissionline' and' theftelephone line; andthe object offjoiirinventionfis. to provide acompact and-r eli-j.- "able device which willprotectthe telephonebodiment of our. inven v vvtionj aj. movable memberfrming part of a; I .'sw'itchjb'yf meansf-of which the I telephone 'circuit',n 1ay be openedjca'rrie's a fuse forfeach line'of' the'telephone'circuit e parke 'apton f negtedrbetween the two lineszoflthe'circuit;

and-alinedischarge-term nalfor each-line of the telephone, circuit 066 vcrating Withe grounde discharge termina adjustable with" relation to theline discharge terminals the 'spajrk gap between the lines of thecircuit; and Fig. '3 a die, ram: showing the relation of cu it; parts ofthe shown in elevation.

In the embodiment of our'invention shown j in the drawings, abase-blockgl icarrie'sinsu lato'rs 2, and aterminal'block 3 mounted on Ione insulator-,1'carriesclips 5,. hilej terminal block 4'1nounted on theother insulato'r car:

ries'clips 6, 1A movable-member or; tube 7,

v 7 ,made offiber' or any-suitable-insulatingmagplion'elllnes,.espec'ially'g-th'ose carriedlon the terial-,' c'arries atne'end; a'-. air'of bladesjffi, one on" each side of the tu fe;connected 'tol ,8, fuse 12 and blade-1:0, and cooperating with when;desired In order to]provide againstencessive dif-I ferencesofpotentialbetweenthe two sides of the telephone circuit, a spark-gap 14, prefer1-ably consisting-ofjtwo carbon locks sepa- L rated by'a sheet of mica ismountedon the tube 7 assliown in'-Figs.,1 and 2, and is held I inposition-hetw'een spring-clips 15, each of which-isconnected'to one lineof the circuit and rnakes an electrical connection between ltlie'li'neandone' side of the spark-gap, as

Iwellas forniinga'mechanical support to hold r the spark-ga .inposition.

. e n excessive I potentialon t p e lines of the telephone circuit isfprevented' by a'spark-gap to ground, and

the preferred form comprises, line-discharge terminals 16 and 17., onemounted on each the .cli s; 6 by means of ipivo tsf9f,.'while a air';ofbla e'silO, securedito the other end -0 the tube 7-, one oneachsid'e thereof, coeperate '70 with'the. clipg'fi fflE'ach of' theblades 8 and J ljO'carries a ably-ioftheinclose sezclip 1 1", and"fusesjl 2", prefer-- I Shrr minded b ty'pe ith-thefuse-wire refractorymaterial, engage v y p v I the clip's andt erebyestablishelectricalcontions-uponlthe' telephone line, regardless-of, L'nectionfbetween{theblades'on eachs'ide of:

I :the-tube 7. 'Anop'erating.I'ingor'handIelK.

i's'ssecurely attached to.-th e 'tube' 7, and the whole structure forms'{a' double-pole knife-. blade switchswinging about the pivots 9,. eachblade ofjthe switch consisting of a blade .of the blades 8,' and therebyconnected to the Ilines of the circuit, and a round-dischar e 7 terminal18 cooperating with tllBllIlG-(llS- charge terminals 16 and 17, andmounted so as vtoibe adjustable transversely of the gap terminal 18 willcause a fuse to blow, thereby the protection of the user of thetelephone.

opening the circuit; although if for any reason the fuse fails to openthe circuit it may be done bymoving the member .7 to lengthen the gapbetween terminal 18fand the other terminals.

The relation of the protective device to the telephone and to thetelephone circuit is shown, for purpose of illustration only, in

Fig. 3. The device is of greatutility in con' nection with any telephonesystem, but is particularly useful in connection with a system such asshown in Fig. 3, in which a telephone 21 is connected to the primary 22of a transformer, the line between the transformer and the telephonebeing protected by a spark-gap 23, which carries any excessive potentialon the lines to the ground. The secondary 24 of the transformer isconnected through the rotective device to the lines 25 and 26 o thetelephone circuit;

The transformer-is interposed between the telephone and the telephonelines to insure against shocks, no matter what the potential of thetelephone-line may be, while the protective device is inserted in theline beyond the transformer, so that abnormal conditions on the lines,such as result from the lines being struck by lightnin or from being incontact Withthe leads 0 a high-tension transmission line, will notdestroy the transformer and therebybring the excessive potential of thetelephone-lineupon the telephone. In case, for any reason, an excessivecurrent flows over the telephone circuit, the fuses 12.

will blow, and thereby open the circuit; if there is an abnormaldifference of otential between the two sides of the telep onecircuit,the spark-gap 14 will break down and,

permit the difference of potential to be e ual mad; while ifthepotential of the telep one line in relation to the ground reaches anabnormal amount, either through the action of lightning or a directcontact of the telephone line with a high-tension system, the gap be--tween the line-discharge terminals 16 and 17 and the groundeddischarge-terminal 18 will break down, and the excessive potential willthereby be relieved. If they excessive potential is due to adirectcontact between the transmission-line and the telephone-line, an arcwould be maintained between the termi- The rounded ease ee rials 16 and1.7 and the grounded terminal 18, wh'ihhg would s'oo'n destr oy. theapparatus. The rush of current "caus d thereby normally -blows thefuses, ithereby opening the circuit,

but if for any reason the circuitis not opened when the are 'forms theswitch may be opened by means of the operating ring 13,. lengthening thegap between the terminals 16 and 17 and the grounded terminal 18 to suchan extentjhat the arc is broken and the device saved from destruction.

Our invention may be embodied in many other forms thanv the forms shownin the drawings, and, we, therefore, do not wish .to

be restricted to the precise form shown and described; but intend tocover by the claims all changes and modifications which are within thespirit and scope of our invention. What we claim as new and desire tosecure by Letters Patent of the United States, is 1. In a protectivedevice for electric circuits, the combination with a switch having amovable blade for each side of the circuit,

of a line discharge terminal mounted on each blade, and a roundeddischarge terminal cooperating both said line terminals when the switchis closed.

2. In a protective device-for electric circuits, the combination with aswitch comprising a base, switch clips secured thereto, a movableinsulating support carrying metallic blades at each end for engagingsaid clips, and a fuse connecting said b ades, of a line dischargeterminal mounted on said insulat- 7 1 J mg support, and a-groundeddischarge telmmal cooperating with said line terminal when the switch isclosed.

3. In a protective device for electric cir cuits, the combination with aswitch comprising a base, two pairs of switch clips secured thereto, aninsulating tube, a air of blades secured at each end of the to e, the

blades of each pair being on opposite sides of the tube and each bladecooperating with one of said clips, and-a fuse on each side of saidtubeconnecting the blades on that side.

4. In a protective device 'for electric circuits, the combination nth aswitch comprising a base, two pairsfof switch fclips se-. cured thereto,an insulfitifitgtubei a air of blades secu'red-at each end'of the tu e,the blades of each pair'being' on opposite sides of the tube and eachblade cooperating with one of said clips, afuse onbachfsidegoi. saidtube connecting the blades on that side, a air of line dischargeterminals carried by sai tube,

one on each side, and a grounded discharge terminal cooperating.therewith when the switch is closed. i

'5. In a protective device for electric circults, the combination withaswitch com prismg a base; two pairs of. switch clips secured'the'reto,an insulatingtub'e, a air of blades secured at eachend of the tu e, theblades of each pair being on opposite sides of the tube and each bladecoeperating with one 1 In witness whereof, We have hereunto set of saidclipsja-fuse on each side ofsaid tube our hands this 13th day of March,1907. connecting the blades on that side, a air of Y v JOHN B. TAYLOR.line dlschar e terminals earned by sam tube, l v :5 one on each side,and a, grounded discharge i DANIEL CARPENTER terminal adjustable withrelation to the'line Witnesses: terminels -and e06 erating therewithwhen BENJAMIN B, HULL, the switch is closed? HELEN ORFORD.

